According to Ben Woodling of Feetbelts:
Fixed Gear Trick Riding is such an evolving sport. We’re just two friends who ride and ride and ride. Being unhappy with current strap availabilities, durability, and environmental sensibility, we decided to create a product that many different types of riders would appreciate. Whether the rider is just beginning to ride fixed gear, a hardened messenger who is looking for something that will last longer at a cheaper cost, or someone who is environmentally friendly and is tired of the plastic and metal waste that comes with broken cages. We originally developed them to appease the local fixed gear community who were tired of their straps and cages breaking. San Marcos is located in the Texas Hill Country and many riders here are looking for something they can ride platform style and still have the ability to strap in to the pedals. Originally designed to replace single straps as a way to increase durability and feet to pedal contact while doing tricks. They are similar to the product you listed but ours does not include the hardware. They technically work as replacement straps although there have been many trial runs that work without the hardware with just two standard cage bolts attached to BMX pedals.
Check out www.myspace.com/feetbelts for more info.